Why: To test how the nerve agent VX behaved when dispersed with artillery shells.

Where: At the Gerstle River site.

Chemical: VX, one of the deadliest nerve agents known; persistent in the environment because it is a sticky liquid that evaporates slowly.

The tests included releasing deadly nerve agents in Alaska and spraying bacteria over Hawaii, according to the documents obtained Tuesday.

The United States also tested nerve agents in Canada and Britain in conjunction with those two countries, and biological and chemical weapons in at least two other states, Maryland and Florida.

The reports of more than two dozen tests show that biological and chemical tests were much more widespread than the military has acknowledged previously. The Defense Department planned to release summaries of 28 chemical and biological weapons tests at a House Veterans Affairs Committee hearing today.

The Pentagon released records earlier this year showing that chemical and biological agents had been sprayed on ships at sea. The military reimbursed ranchers and agreed to stop open-air nerve agent testing at its main chemical weapons center in the Utah desert after about 6,400 sheep died when nerve gas drifted away from the test range.

But the Pentagon never before has provided details of the Alaskan, Hawaiian, Canadian and British tests. The Defense Department planned to formally release summaries of 28 biological and chemical weapons tests at a House Veterans Affairs subcommittee hearing Wednesday.

The documents did not say whether any civilians had been exposed to the poisons. Military personnel exposed to weapons agents would have worn protective gear, the Pentagon says, although the gas masks and suits used at the time were far less sophisticated than those in use today.

Troops involved in biological weapons testing were vaccinated ahead of time, said Dr. William Winkenwerder Jr., the Pentagon's top health official. In prepared testimony for the House panel, Winkenwerder acknowledged that some service members involved in the tests "may not have known all the details of these tests."

He said some service members participating in tests using simulated chemical or biological weapons may not have been informed about the tests at all.

The head of the House Veterans Affairs panel called for further investigation of the tests.

"Our focus must be on quickly identifying those veterans who were involved, assessing whether they suffered any negative health consequences and, if warranted, providing them with adequate health care and compensation for their service," said Rep. Chris Smith, R-N.J.

The tests were part of Project 112, a military program in the 1960s and 1970s to test chemical and biological weapons and defenses against them. Parts of the testing program done on Navy ships were called Project SHAD, or Shipboard Hazard and Defense.

The United States scrapped its biological weapons program in the late 1960s and agreed in a 1997 treaty to destroy all of its chemical weapons.

Some of those involved in the tests say they now suffer health problems linked to their exposure to dangerous chemicals and germs. They are pressing the Veterans Affairs Department to compensate them.

Earlier this year, the Defense Department acknowledged for the first time that some of the 1960s tests used real chemical and biological weapons, not just benign stand-ins.

The Defense Department has identified about 5,000 service members involved in tests at sea and another 2,100 involved in the tests detailed Wednesday, said Dr. Jonathan Perlin of the Department of Veterans Affairs. He said 53 veterans had filed health claims for their exposure during the tests. The VA has sent letters to 1,400 veterans involved in the tests at sea, Perlin said.

VA and Pentagon officials acknowledged at a July hearing that finding the soldiers has been difficult.

Besides the test sites in Alaska, other sites described in the latest Pentagon documents include:

 Big Tom, a 1965 test that included spraying bacteria over the Hawaiian island of Oahu to simulate a biological attack on an island compound, and to develop tactics for such an attack. The test used Bacillus globigii, a bacterium believed at the time to be harmless. Researchers later discovered the bacterium, a relative of the one that causes anthrax, could cause infections in people with weakened immune systems.

 Rapid Tan I, II, and III, a series of tests in 1967 and 1968 in England and Canada. The tests used sarin and VX, as well as the nerve agents tabun and soman, at the British chemical weapons facility in Porton Down, England. Tests at the Suffield Defence Research Establishment in Ralston, Canada, included tabun and soman, the records show.

Tabun and soman are chemically related to sarin and produce similar effects.